I'm obsessive/compulsive, so I have enough of these to write a book.My most pervasive habits are counting and touching. I count things and organize them in sets of magic numbers and I touch things or draw lines on them with my finger to tell myself that whatever the object is is "set." I don't expect that to make any sense, but those are two of my weird habits.
Oh, those things make perfect sense to someone else with OCD. My wife does weird things like that too.